Log Washers

Log Washers are designed to remove tough, plastic clay contaminants and other deleterious materials from gravel, stone and hard ore feeds via material-on-material scrubbing.


How Log Washers Work

Log Washers remove clays and other deleterious materials by material-on-material inter-particle scrubbing, as well as the interaction with the paddle shafts and water. Clay contaminated hard rock and ore is subjected to a more aggressive washing action than any other type of machine available. Intermeshing paddle shafts scrub and convey the material over the machine length to the discharge, while dissolved clay and mud contaminates overflow a weir in a water slurry when a Log Washer is installed at a proper slope.

Log Washers sit at a slope of zero to 14 degrees depending on the severity of the washing action required. As the percentage of deleterious material increases, the slope must be raised to increase retention time. Under certain conditions, lower slope can increase the capacity while decreasing usage power and wear. It is recommended to establish the lowest operating slope while maintaining a clean product to take advantage of low usage power consumption and parts wear.

As deleterious material is liberated, clean material moves forward between the shafts and discharges out the bottom of the box after a final rinse by a spray bar. Deleterious clays and silts are dissolved and absorbed into the water and carried over a weir on either side of the box. In high capacity applications, an optional rising current system helps lift waste fractions to the top of the water level and over the weir.

When selecting a Log Washer, the type of feed material must be taken into consideration. The size and shape of the feed material can affect the capacity of a particular size unit. McLanahan will be able to provide a list of capacities and water requirements based on your feed material.

It is recommended that the sand-sized fraction is removed prior to the Log Washer since finer material tends to cushion the washing action. The sand fraction should only be fed to the Log Washer when severe washing of fines is required. When processing fines, it is necessary to capture the overflow of the unit to save them for further processing. 

McLanahan Log Washers can accept a feed material up to 6″ (150mm) cubed. As the percentage of material to be removed increases, longer units should be used to increase the retention time washing action. In very severe applications, two or more Log Washers may be required.

Feeds having up to 15% clays can be removed in a single Log Washer. While the machine has a spray bar near the discharge for an additional rinsing in most instances, it is recommended that the rock or ore be further washed and, as required, separated on a washing/vibrating screen.

Why McLanahan Log Washers

While there are many things that set the McLanahan Log Washer apart in the market, when you work with McLanahan, you are working with the company that perfected the Log Washer. In 1891, Samuel Calvin McLanahan was granted a patent for an ore washing, twin steel shaft machine that is today’s Log Washer. Just as when Samuel Calvin McLanahan originally engineered them, producers can be sure that McLanahan Log Washers today are designed with safety and simplicity of operation in mind, and they are backed by McLanahan's process knowledge to ensure their profitable operation.

McLanahan offers Log Washers with shafts up to 10.6m (35') in length. The length of the Log Washer directly affects the retention time of the material being washed. The longer the washer box, the higher the retention time. There are also several diameters of shaft available. In general, the 36” and 38” diameter Mudmaster units can accept a feed material up to 4” cubed, while the 46” diameter Super Mudmaster units can accept a feed material up to 6” cubed.  

McLanahan Log Washers come standard with adjustable weirs at the overflow openings that permit the change in water depth, and can in turn affect the quality of the washed products. All units are equipped with a spray bar for rinsing material prior to discharge. McLanahan recommends that a rinsing screen be used after a Log Washer to provide a final wash. As an option, McLanahan supplies cleanout grates at the bottom of the Log Washer to aid in cleaning the unit of material should maintenance or seasonal shutdowns occur.

All McLanahan Log Washers employ a V-belt driven, single-input, dual-output gear reducer that can be uncoupled from the log shafts and frame for maintenance. Heavy-duty washer boxes are diagonally reinforced on the bottom and vertically along the sides to provide years of maintenance-free use. Standard drive guards and optional top covers are available for personnel protection.

Frequently Asked Questions About Log Washers

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  • 36″ (91.4 cm) diameter paddle swing  available in 25′ (7.6m) and 30′ (9.1m) lengths
  • 38″ (96.5 cm) diameter paddle swing  available in 30′ (9.1m) and 35′ (10.6m) lengths

Super Mudmaster

  • 46″ (116.8 cm) diameter paddle swings  available in 30′ (9.1m) and 35′ (10.6m) lengths

The cost of a Log Washer varies based on the size. Contact McLanahan or your nearest authorised local dealer not only for pricing, but for discussions on suitability and use for your application.

You should know the type of clay/silt contamination that needs removed, the ore/rock feed size, the tons per hour feed solids capacity, and the process flow and equipment location of the required washer in your processing plant.

Consider Blade MillsCoarse Material Screw Washers, Rotary Scrubbers (barrel washers), Trommel or Vibrating Wash Screens and Combination Rotary Scrubber Trommel Screens.

Consider V-belt drive guards and top protective safety covers.

Log Washers are widely used for washing materials, including hard rock ore, gravel, limestone and phosphate, that have tough, plastic sticky clay contaminants.

Features & Benefits
  • Log shafts are fabricated from extra-heavy, one-piece steel pipe and flanged at both ends to facilitate maintenance.
  • Bolt-on, abrasion-resistant paddles are affixed to a twin shaft design to ensure an aggressive washing action that breaks down even the toughest clays.
  • Twin-Seal Pak submerged rear bearing assemblies incorporate Caterpillar Duo-Cone® seals that keep water and even the smallest particles from reaching the bearings.
  • McL5X paddles are made of specially developed fine grain steel for optimum hardness and maximum abrasion resistance.
  • Cleanout gates are available and positioned at the underside of the washer box.
  • Spiral or straight row paddle configuration on the shafts are available.
  • Capacities of up to 500 tph are available in a single X-Treme Super Mudmaster Log Washer.

Need Some Help?

Our customer service team is here to help you 24/7. We can ship you parts, send field service technicians to your site and answer any questions you have. Whatever you need, we are here for you.